/*!	 synfig/rendering/common/optimizer/optimizerblendzero.cpp
**	 OptimizerBlendZero
**
**	......... ... 2015 Ivan Mahonin
**
**	This package is free software; you can redistribute it and/or
**	modify it under the terms of the GNU General Public License as
**	published by the Free Software Foundation; either version 2 of
**	the License, or (at your option) any later version.
**
**	This package is distributed in the hope that it will be useful,
**	but WITHOUT ANY WARRANTY; without even the implied warranty of
**	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
**	General Public License for more details.
**
*/

#ifdef USING_PCH
#	include "pch.h"
#else
#ifdef HAVE_CONFIG_H
#	include <config.h>
#endif

#ifndef _WIN32
#include <unistd.h>
#include <sys/types.h>
#include <signal.h>
#endif

#include <synfig/general.h>
#include <synfig/localization.h>

#include "optimizerblendzero.h"

#include "../task/taskblend.h"
#include "../task/tasksurfaceempty.h"

#endif

using namespace synfig;
using namespace rendering;

void
OptimizerBlendZero::apply_zero(const RunParams &params, const TaskBlend::Handle &blend, const Task::Handle &task) const
{
    if (!task || !task->valid_target()) {
        Task::Handle empty = new TaskSurfaceEmpty();
        empty->target_surface = params.ref_task->target_surface;
        apply(params, empty);
        return;
    }

    if (task->target_surface == blend->target_surface) {
        apply(params, task);
        return;
    }

    apply(params, task->clone());
    params.ref_task->target_surface = blend->target_surface;
    params.ref_task->move_target_rect(
        blend->get_target_offset()
        - task->get_target_offset()
        + (task == blend->sub_task_a() ? blend->get_offset_a() : blend->get_offset_b()));
    assert(params.ref_task->check());
}

void
OptimizerBlendZero::run(const RunParams& params) const
{
    TaskBlend::Handle blend = TaskBlend::Handle::cast_dynamic(params.ref_task);

    if (blend
            && blend->target_surface
            && blend->sub_task_a()
            && blend->sub_task_a()->target_surface
            && blend->sub_task_b()
            && blend->sub_task_a()->target_surface) {
        bool zero_amount = fabsf(blend->amount) <= 1e-6;

        if (zero_amount) {
            apply_zero(params, blend, blend->sub_task_a());
            return;
        }

        bool valid_a = blend->sub_task_a()->valid_target();
        bool valid_b = blend->sub_task_b()->valid_target();

        if (!valid_b && !valid_a) {
            apply_zero(params, blend, Task::Handle());
            return;
        }

        bool one_amount = fabsf(blend->amount - 1.f) <= 1e-6;
        bool intertsects = valid_a && valid_b
                           && etl::intersect(
                               blend->sub_task_a()->get_target_rect() + blend->get_offset_a(),
                               blend->sub_task_b()->get_target_rect() + blend->get_offset_b());

        if (one_amount && !intertsects) {
            bool onto = Color::is_onto(blend->blend_method);
            bool straight = Color::is_straight(blend->blend_method);

            if (onto && straight) {
                apply_zero(params, blend, Task::Handle());
                return;
            }

            if (onto) {
                apply_zero(params, blend, blend->sub_task_a());
                return;
            }
        }
    }
}